Telephone apparatus.



C. I. BRADBURN. TELEPHONE APPARATUS.

APPLICATION FILED JAN. 20, 1908.

Patented May 10, 1910.

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C. F. BRADBURN. TELEPHONE APPARATUS.

APPLICATION FILED JAN.20, 1908.

957,496, Patented May 10, 1910.

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%%%MA' 7 K4 flea/ 44 ENE snares manner 1 risen CHARLES FRANKLIN BRADBURN, OF DEL'MER, ONTARIO, CANADA.

TELEPHONE APPARATUS.

To all whom it may concern:

Be it known that I, CHARLES FRANKLIN Bnnnnumv, of Delmer, in the county of OX- ford, in the Province of Ontario, Canada, have invented certain new and useful Improvements in Telephone Apparatus; and I hereby declare that the following is a full, clear, and exact description of the same.

In my concurrent application #887,9it), for telephone apparatus, I have shown and described a telephone system comprising a series of telephone stations each of which is provided with a selecting instrument forming part of the telephone system, each selecting instrument consisting of a primary mechanism and a. secondary mechanism, with a selecting circuit normally without current closed through the primary and secondary mechanisms of the selecting instruments of all the telephone stations to connect them in series, and a separate selecting battery for each selecting instrument arranged to be cut into the selecting circuit by the operation of the primary mechanism of its respective selecting instrument. Each primary mechanism consists of a primary dial having a series of contact points and a primary pointer arranged to successively engage the contact points during its movement on the dial, and close its respective selecting battery through the selecting circuit and through the secondary mechanisms of the remaining instruments connected in series, and create an impulse in the selecting circuit for each contact point that it engages, during its movement on the primary dial. Each secondary mechanism is provided with a secondary pointer and an actuating mechanism for the pointer operated by the impulse of the current through the selecting circuit. The primary pointer creates an impulse, in the selecting circuit, for each contact point it engages, and the impulse in the selecting circuit creates a corresponding movement of the secondary pointer of its respective secondary mechanism and the secondary pointer of the remaining secondary mechanisms so that any one telephone station can establish acommunication with any other telephone station in the series.

It is possible in the telephone system described in the above application for any other telephone station to operate the primary pointer of its selecting instrument and disarrange the telephonic circuits between Specification of Letters Patent.

Application filed January 20, 1908.

Patented May 10, 1910.

Serial No. 411,731.

the two telephone stations which may be in communication.

The object of the present invention is to provide a locking mechanism by which the primary pointers of all the remaining selectmg instruments in the series can be locked out of action by the movement from zero of the primary pointer of any one selecting instrument which may be termed the calling mstrument, so that the telephonic communication between the connected stations cannot be disarranged until the primary pointer of the calling instrument has returned to zero.

A further object of the invention is to so arrange this locking mechanism that coincident with the return of the operated pri mary pointer to zero, the primary pointers of all the other instruments will be released to permit of telephonic communication being established between any other group of two telephone instruments.

For an understanding of the invention reference is to be had to the following description and to the accompanying drawings in which;-

Figure l, is a view of a part of the primary and secondary mechanisms showing the locking means for the primary pointer and the manner in which it is operated by the secondary mechanism. Fig. 2, is a side view of the secondary pointer. Fig. 3, is a side view of the locking means. Fig. 4:, is a detail view of the means for moving the secondary pointer.

Like characters of reference refer to like parts throughout the specification and drawings.

Each selecting instrument consists of a primary mechanism, and a secondary mechanism. The primary mechanism is provided with a primary dial at, having a central stud a on which is revolubly mounted the hub of the primary pointer 79. On the primary dial a are a series of indicating points numbered respectively from 0 to 40, but the number of indicating points must be at least equal to the number of instruments in series in the circuit. On the primary dial concentric with the center thereof is a conductor f, preferably of an annular shape having a series of projecting contact points 9, radially alined with the center of the primary dial and the numbered indicating points thereon. Concentric with the conductor f and located between the conductor and the center of the primary dial is a broken contact ring Z), with the broken part of the ring radially alined with the zero point 0, and the center of the dial. Contained between the ends of the broken contact ring Z) and electrically disconnected therefrom, is a contact plate 0 to which is electrically connected the main relay conductor (Z. On the annular conductor f and alined with the contact plate 0, and zero point, is an are shaped contact plate It, of a greater are than the contact plate 0. hen the pointer Z) of the primary dial is at zero, it establishes an electrical connection between the contact plates 0 and h, for the incoming current to the local relay conductor 0 electrically connected with the contact plate It, and with the binding post j of the relay k so that the current can circuit from the main relay conductor (Z by means of the contact plate 0, and primary pointer b to the contact plate 7L, and local relay conductor c to the relay is, and through the coils of the relay is to the binding post Z, to which is connected the main relay conductor (Z, leading to the next instrument.

Connected to the main relay conductor (Z, and to the contact ring Z), are the conductors (Z of the relay actuating battery 6. Owing to the absence of an electrical connection between the contact ring Z), and the contact plate 0, the battery 6 is normally in an open circuit, while the primary pointer Z) is at Zero, but while the primary pointer is at zero, a closed circuit is maintained from the main relay conductor (Z, to the relay so that all incoming currents on the relay conductor (Z can circuit to the relay is and actuate it to close the local battery 6 through the electromagnet f and cause the movement of the secondary pointer g. hen the primary pointer Z2 is moved from zero, it breaks the circuit from the contact plate 0 to the contact plate It, and engages the contact ring 6 with which it remains in contact until it completes the circle of its revolution on the primary dial from 1 to 40. The contact plate h, and the contact plates 9, of the conductor f, are successively engaged by the primary pointer as it moves on the primary dial, but there is no connection between the primary pointer and conductor f other than through the contact plates g. hen the primary pointer is moved from the contact plate 72, the circuit of the incoming current-s on the main relay conductor (Z is interrupted, and the circuit of the current from the positive pole of the battery e, is closed through the contact ring Z), and primary conductor Z)- to the contact plate 9 and conductor 7, to the local relay conductor 0 and relay 70, as the primary pointer successively engages the contact points 9 during its revolution. As the primary pointer 6 moves from the contact plate h, to the first contact plate g,

and thereafter as itsuccessively engages the remaining contact plates 9, the circuit of the battery 6 is alternately broken and closed through the relay is to provide for the articulation of the armature of the relay 70. hen the primary pointer engages the contact plate g, radially alined with the center of the primary dial and the first indicating number thereon, a circuit is closed from the positive pole of the battery 6 to the relay is, so that the current from the battery 6, will energize the relay and attract the armature h and then pass from the relay is, of the operated selecting instrument, to that of the next selecting instrument, and so on through all the selecting instruments connected in series until it returns again to the negative pole of the battery 6, of the operated selecting instrument. When the primary pointer passes from the first contact plate g, the circuit of the current from the battery 6, is opened to deenergize the relay 7; and permit of the armature it of the relay 7c resuming its normal position. hen the primary pointer engages the second contact plate 9, the circuit for the current from the battery 6, is again established to the relay is, the continued movement of the pointer alternately closing and opening this circuit so that the armature h will be attracted and released as the primary pointer engages each contact plate 9 and passes from it. The action of the relays of all the selecting instruments in the series, is coincident with the action of the relay of the operated selecting instrument.

The armature h oscillates in the armature frame 2" and connected to the armature frame i and insulated therefrom is a binding post 7' for the conductor Z of the local battery 6', and electrically connected with the armature h is a binding post is for the other conductor m of the local battery 6. The binding post j is positioned in the armature frame 2" to be engaged by the armature h when attracted by the magnet of the relay is to close the circuit of the local battery 0 through the electromagnet f. One section of the battery conductor Z is connected with the binding post 0 and the other section of the battery conductor Z is connected with the other binding post p. of the electromagnet f. Then the armature h is attracted to the magnet of the relay Zc, a circuit for the local battery current will be closed from the local battery 6 to the binding post 0 through the electromagnet f to the binding post p and from the binding post p by means of the other section of the battery conductor Z to the binding post j, armature 7L, and binding post 70, conductor m to the battery 6. hen the electromagnet f is energized it attracts the armature and when deenergized it allows the armature g to return to its normal position. The armature forms one arm of a bell crank lever 'r. The lever r is fulcrumed between the points of the pivot screws 8, and each attraction of the armature causes the lever r to oscillate and move the arm 6 into engagement with one of the ratchet teeth a formed on the hub o of the secondary pointer 9. Each engagement of the arm t with a ratchet tooth u moves or revolves the hub o a distance equal to the motion of the arm 6 which is preferably the distance of one of the ratchet teeth, and each movement of the hub 0/ causes a corresponding movement of the secondary pointer g. The distance of the movement of the secondary pointer corresponds with the distance between each adjacent pair of contact points g, so that the movement of the secondary pointers of all the instruments will correspond in time and distance with the movement of the operated primary pointer. The number of ratchet teeth on the hubs of the secondary pointers corresponds with the number of sub-divisions of the primary dials so that one complete revolution of the primary pointer of the selecting instrument will cause a complete revolution of all the secondary pointers of the instruments in series.

Each secondary pointer g revolves on a stud w projecting centrally from the secondary dial a? and concentric with the stud to is a broken contact ring y. The spaces between the ends of the broken contact rings 3 are differently located in the various instruments and each space is positioned to correspond with its respective calling number. As shown in Fig. 1, this space is radially alined with the center of the hub and the number 1, and contained in the space between the ends of the broken contact ring is a contact plate a electrically disconnected from the contact ring y. When the sec ondary pointer engages the contact plate a a signal circuit is established through its respective telephone instrument. When the primary pointer Z) of the calling instrument has positioned the secondary pointer g of the called instrument to engage with the contact plate a, telephonic communication is established between them as described in the above named application. It is possible however by the movement of the primary pointer of the other instruments, in the series from Zero to the first or any succeeding contact plate on the primary dial to create an impulse or impulses through the selecting circuit and displace the secondary pointer of the called instrument from its contact plate a and disarrange the telephonic communication between the calling and called telephone stations. To prevent a contingency of this kind each selecting instrument is provided with a locking device for the primary pointers normally in an inoperative position so that while the primary pointers are at zero any one of them can be moved from there to the first contact plate on the primary dial, and when moved to the first contact plate the locking devices of all the instruments in series will be brought into an operative position to lock the primary pointers of the re maining instruments at zero co-incident with the engagement of the operated primary pointer with the first contact point on the primary dial. This locking device may be described as consisting of a bell crank lever a fulcrumed between the primary and secondary pointers with one arm 12 arranged to be engaged by the secondary pointer and the other arm 0 carrying a detent tooth c to move into the path of the primary pointer. lVhen the secondary pointer g is at zero it engages the arm 22 of the bell crank lever and positions the latter to hold the other arm 0 and the detent teeth 6 clear of the path of the primary pointer so that the primary pointer, when it and the secondary pointers are at zero, can move from zero to the first contact plate 9. When the primary pointer b engages the first contact plate 9, it creates an impulse through the selecting circuit which moves the secondary pointer of the operated primary pointer and the secondary pointers of all the remaining selecting instruments from zero to simultaneously release the bell crank levers so that the detent teeth 6 can move into the paths of the primary pointers of the remaining instruments to prevent those primary pointers being moved from zero to the first contact plate. The primary pointer of the operated instrument can complete the circle of its revolution and successively pass the contact plates of its respective primary dial and create an impulse through the selecting circuit for each contact plate which it passes and cause the co-incident movement of the secondary pointers until the secondary pointer of the selected instrumentv comes into engagement with the contact plate a and establishes telephonic communication between the calling and called telephone stations. The telephonic communication can be carried on between these stations without interruption by any of the other instruments moving the primary pointer from zero to the first or any succeeding contact plate g. To accelerate the action of the bell crank lever a a spring f is connected to the arm 0 and to a tension device 57* suitably connected to the frame work of the mechanism. The arm 6 is provided with a traveler h projecting at right angles from the end of the arm to be engaged by a lifting finger 2' carried by the disk 9' secured to the end of the secondary point-er. Vhen the primary pointer has completed the circle of its revolution and returned to zero, the lifting finger i carried by the secondary pointer engages under the traveler 72, and positions the bell crank lever to move the detent tooth from the path of the primary pointer. The action of the secondary pointers of all the instruments in returning to zero and their effect on the bell crank levers being coincident with the action of the secondary pointer of the operated instrument.

Having thus fully described my invention what I claim as new and desire to secure by Letters Patent is 1. A telephone system comprising a selecting instrument consisting of a primary mechanism and a secondary mechanism, a primary pointer, a series of contacts for the primary mechanism, a secondary pointer for the secondary mechanism actuated by the engagement of the primary pointer with the contacts and a locking mechanism for the primary pointer positioned directly in the path of the latter by the movement of the secondary pointer as the primary pointer engages the first contact from zero and removed from the path of the primary pointer when the secondary pointer returns to zero.

2. A telephone system comprising a number of selecting instruments each consisting of a primary mechanism having a series of contacts and a primary pointer, a secondary mechanism having a secondary pointer and an actuating means for the secondary pointer, a selecting circuit through the primary pointer and contacts of the primary mechanism to the actuating means of the secondary pointer, and a locking means for the primary pointer normally held free from engagement with the latter by the secondary pointer and positioned directly in the path of the primary pointer by the movement of the secondary pointer from zero.

3. A telephone system comprising a selecting instrument consisting of a primary mechanism having a primary pointer, a sec ondary mechanism having a secondary pointer, a bell crank lever having two arms, a detent carried by one of the arms to engage with the primary pointer, a traveler carried by the other arm to be engaged by the secondary pointer and a spring connected to the bell crank lever to accelerate its movement.

4. In a telephone apparatus a selecting instrument comprising a primary mechanism having a primary pointer and contacts engaged by the primary pointer, and a secondary mechanism controlled by the contacts having a secondary pointer, and means actuated by the secondary pointer controlling the movement of the primary pointer from its initial position.

5. In a telephone apparatus a selecting instrument comprising a primary mechanism having a primary pointer and contacts engaged by the primary pointer, and a secondary mechanism controlled by the contacts having a secondary pointer, a bell crank lever having a detent to engage with the primary pointer, and means engaged by the secondary pointer to position the bell crank lever during the movement of the secondary pointer to arrest the primary pointer at its initial position.

6. In a telephone apparatus a selecting instrument comprising a primary mechanism having a primary pointer and contacts engaged by the primary pointer, and a secondary mechanism controlled by the contacts having a secondary pointer, a bell crank lever having a detent to engage with the primary pointer, means engaged by the second ary pointer to position the bell crank lever during the movement of the secondary pointer to arrest the primary pointer at its initial position, and a spring connected to the bell crank lever accelerating its movement. 7

7. In a telephone apparatus a selecting instrumentcomprising a primary mechanism having a primary pointer and contacts engaged by the primary pointer, a secondary mechanism controlled by the contacts having a secondary pointer, a bell crank lever having two arms, a detent carried by one of the arms to engage with the primary pointer and arrest it at its initial position, and a traveler carried by the other arm to be engaged by the secondary pointer.

8. In a telephone apparatus a selecting instrument comprising a primary mechanism having a primary pointer and contacts engaged by the primary pointer, and a secondary mechanism controlled by the contacts having a secondary pointer and a locking mechanism for the primary pointer at its initial position controlled by the movement of the secondary pointer.

9. In a telephone apparatus a selecting instrument comprising a primary mechanism having a primary pointer and contacts engaged by the primary pointer, and a secondary mechanism controlled by the contacts having a locking mechanism positioned to arrest the movement of the primary pointer from its initial position during the movement of the secondary pointer.

Delmer, Ontario, December 26th, 1907. CHARLES FRANKLIN BRADBURN. Signed in the presence of JOHN IVIXON HILBORN, MARY HORNE. 

